WO2022202333A1

WO2022202333A1 - Phenolic resin mixture, and curable resin composition and cured product thereof

Info

Publication number: WO2022202333A1
Application number: PCT/JP2022/010360
Authority: WO
Inventors: 篤彦長谷川; 政隆中西; 一真井上
Original assignee: 日本化薬株式会社
Priority date: 2021-03-23
Filing date: 2022-03-09
Publication date: 2022-09-29
Also published as: TW202302693A; KR20230158497A; CN117043219A; JPWO2022202333A1; JP7160511B1

Abstract

A phenolic resin mixture comprising (A) a phenolic resin represented by formula (1) or (2) and (B) a crystalline alkyl-substituted biphenol compound having a melting point of 70 to 300°C, in which the ratio of the weight of the component (A) to the weight of the component (B) is 95/5 to 85/15. (In formula (1), a plurality of R₁s and ps are present independently, R₁s independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, a methoxy group, an ethoxy group, a nitro group, a nitrile group, an amino group, or a phenyl group which may have the same substituent as mentioned above, ps independently represent a real number of 0 to 3, and n is the number of repeats and represents a real number of 1 to 20.) (In formula (2), a plurality of R₁s and ps are present independently, and R₁s independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, a methoxy group, an ethoxy group, a nitro group, a nitrile group, an amino group, or a phenyl group which may have the same substituent as mentioned above, ps independently represent a real number of 0 to 3, and n is the number of repeats and represents a real number of 1 to 20.)

Description

Phenolic resin mixture, curable resin composition and cured product thereof

The present invention relates to a phenolic resin mixture, a curable resin composition, and a cured product thereof.

　In the field of semiconductor encapsulants, phenolic resins are used as curing agents for epoxy resins. In recent years, along with its development, the resin composition has been improved in terms of moisture resistance, adhesion, dielectric properties, low viscosity for high filling of fillers (inorganic or organic fillers), and shortening of the molding cycle. Further improvements in various properties such as increased reactivity are required.

In addition, the shape of the semiconductor package has become more complicated with thinning, stacking, systemization, and three-dimensionalization in accordance with the change, and the pitch of the wire wiring is becoming narrower and finer. Poor fluidity of the resin composition induces wire sweep. Furthermore, a burden is placed on the connection portion of the wire, which has an adverse effect.

Furthermore, in flip-chip type packages, a method called mold underfill (hereinafter referred to as "MUF"), which seals at once without using underfill, is attracting attention from the viewpoint of a low-cost manufacturing method. In this method, the resin needs to pass through a very narrow gap between the chip and the package substrate, so miniaturization of the filler is important. The viscosity of the system increases, causing voids (air gaps) to occur.

In addition, the sealing resin used in the rewiring layer of wafer-level packages and the correlative insulating film used in the build-up layer must be thin. Since it is necessary to fill the resin composition with a filler, it is also desired to lower the viscosity of the resin composition.

Japanese Patent Application Laid-Open No. 2003-41096 Japanese Patent Application Laid-Open No. 2013-87137

There are various methods for reducing the viscosity, but the most common method is to reduce the viscosity by reducing the molecular weight of epoxy resins and phenolic resins. However, if the epoxy resin or phenol resin is made to have a low molecular weight, the shape at room temperature (for example, 20 ° C. in this application) tends to have fluidity, so it is difficult to handle at room temperature (liquid-starch syrup- Semi-solid, etc.), and furthermore, when it is made into a resin composition, it becomes sticky, making storage and handling difficult.

Specifically, when delivering materials from resin manufacturers to composition manufacturers, they must be frozen and transported, which leads to a large amount of energy consumption. In addition, it becomes unhandleable due to blocking (agglomeration) due to temperature rise during transportation. In addition, even if there is no problem in the transportation process, it cannot be used unless it is returned to room temperature when it is used by the composition manufacturer. Problems such as clogging at the entrance of the hopper may occur during charging. Furthermore, even if an attempt is made to grind the resin composition with a ball mill or the like in order to mix the resin composition homogeneously, it cannot be ground, and the resin composition solidifies in the pot, resulting in damage to the apparatus. Similar problems also arise in the finished composition.

To address these issues, the use of crystalline epoxy resins is being studied (Patent Document 1). However, there are problems such as that there is a limit to the decrease in fluidity during molding, and that it is difficult to maintain handling properties due to the loss of crystallinity due to mixing with phenol resin after making a composition. In general, when a crystalline epoxy resin is used, it must be kneaded at a temperature above the melting point of the crystalline epoxy resin in a kneader, otherwise the epoxy resin will not be sufficiently melted and uniformly dispersed. The molded product of the resin molding material becomes non-uniform, and the strength of the molded product differs depending on the part, so that the characteristics of the semiconductor device deteriorate. However, if the temperature of this molten mixture is high during melt-kneading, the curing reaction proceeds in the kneader, which may lead to a decrease in fluidity and the generation of gelled substances that cause unfilling during molding. . Or, since recrystallization occurs due to high crystallinity, the crystallinity remains even after heat kneading, and this residual crystal melts only during molding, resulting in low curability, burrs and voids, and poor curability. There is a possibility that the formed semiconductor device may be inferior in formability, such as stains being likely to be formed on the surface thereof.

On the other hand, there are attempts to introduce crystallinity into phenolic resins, but due to the high crystallinity, crystallization progresses locally, making it difficult to obtain a homogeneous resin composition. On the other hand, in Patent Document 2, in order to solve the problem of undissolved residue when using a crystalline phenol compound, a quaternary phosphonium compound in a molten state is used as a solvent, and a crystalline phenol compound is added to the solvent. It discloses that the complete dissolution provides a molten mixture that does not leave undissolved parts and has excellent storage stability. However, since it involves heating and melting at about 100° C., there is a possibility that a stable and homogeneous resin composition cannot be obtained when cooled to room temperature.

In view of the above-mentioned actual situation, the present inventors have made intensive studies, and as a result, have found a phenolic resin mixture that is semi-crystalline at 20°C and has both fluidity and handleability, and have completed the present invention.

That is, the present invention relates to the following [1] to [5].
[1]
containing a phenolic resin (A) represented by the following formula (1) or the following formula (2) and a crystalline alkyl-substituted biphenol compound (B) having a melting point of 70 to 300° C.; Phenolic resin mixtures in which the weight ratio of component (B) is from 95/5 to 85/15.

(In formula (1), multiple R ₁ and p exist independently, and R ₁ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, a methoxy group, an ethoxy group, a nitro group, a nitrile group, an amino group, or a phenyl group which may have the same substituents as described above, p is a real number of 0 to 3. n is a repeating number and is a real number of 1 to 20.)

(In formula (2), multiple R ₁ and p exist independently, and R ₁ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, a methoxy group, an ethoxy group, a nitro group, a nitrile group, an amino group, or a phenyl group which may have the same substituents as described above, p is a real number of 0 to 3. n is a repeating number and is a real number of 1 to 20.)
[2]
The phenolic resin mixture according to [1] above, which exhibits a semi-crystalline state at 20° C. and has a hydroxyl equivalent of 130 to 200 g/eq.
[3]
The phenolic resin mixture according to the preceding item [1] or [2], which has an ICI melt viscosity (cone-plate method) at 150° C. of 0.001 to 0.20 Pa·s.
[4]
A curable resin composition containing the phenolic resin mixture according to any one of [1] to [3] above and an epoxy resin.
[5]
A cured product obtained by curing the curable resin composition according to [4] above.

Since the phenolic resin mixture of the present invention has very high fluidity and excellent handling properties, it contributes to productivity, and is used as an insulating material for electric and electronic parts, laminates (printed wiring boards, build-up boards, etc.) and carbon fiber reinforced composite materials. (hereinafter also referred to as "CFRP"), various composite materials, adhesives, paints and the like. It is particularly useful as a semiconductor encapsulating material for protecting semiconductor elements.

The phenol resin mixture of the present invention comprises a phenol resin represented by the following formula (1) or formula (2) (hereinafter also referred to as component (A)) and a crystalline alkyl having a melting point of 70 to 300 ° C. It contains a substituted biphenol compound (B) (hereinafter also referred to as component (B)).

(In formula (2), multiple R ₁ and p exist independently, and R ₁ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, a methoxy group, an ethoxy group, a nitro group, a nitrile group, an amino group, or a phenyl group which may have the same substituents as described above, p is a real number of 0 to 3. n is a repeating number and is a real number of 1 to 20.)

R ₁ in the above formulas (1) and (2) is preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, A hydrogen atom is particularly preferred. Preferably, p is a real number of 0 or 1, particularly preferably 0.

The value of n in the formulas (1) and (2) is the value of the number average molecular weight obtained by measurement of phenolic resin gel permeation chromatography (GPC, detector: RI), or each of the separated peaks can be calculated from the area ratio of

The value of n in the formulas (1) and (2) is usually 1-20, preferably 1.1-20, more preferably 1.1-10. If n is less than 1, the crystallinity is so strong that a homogeneous resin mixture cannot be obtained even by mechanical kneading. On the other hand, when n is larger than 20, the melt viscosity is high, and it is difficult to use from the viewpoint of fluidity and high filler filling.

The phenolic resins represented by the above formulas (1) and (2) can be synthesized based on publicly known synthesis methods, but can also be easily obtained from the market. For example, the phenolic resin represented by the formula (1) is KAYAHARD GPH-65 (manufactured by Nippon Kayaku Co., Ltd., softening point 65°C), and the phenolic resin represented by the formula (2) is MEHC-7840-4S ( available from Meiwa Kasei Co., Ltd., softening point 58-65°C).

Component (B) is a biphenol compound with improved compatibility with component (A) by introducing an alkyl group. A semi-crystalline phenolic resin mixture can be obtained by semi-melting and mixing the crystalline components to homogenously disperse them. In the present application, the term "semicrystalline" refers to a state in which the resin is turbid and not transparent, and in which fine crystals are uniformly dispersed in the resin. In the present application, the crystalline alkyl-substituted phenol resin is not completely melted, but is dispersed while maintaining the crystalline state to form a homogeneous semi-crystalline resin composition. It achieves both fluidity and handling characteristics.
In other words, it can be used as a phenolic resin mixture with component (A) containing component (B) as an organic filler as a matrix.

Therefore, in the present application, it is important to knead the component (B) at a temperature below the melting point and uniformly disperse it in the resin matrix. After kneading, whether or not the phenolic resin mixture maintains a crystalline state and is uniformly dispersed can be determined by visually confirming the appearance of the phenolic resin mixture after preparation. For example, if the resin and crystal clumps are dispersed unevenly, it indicates that the biphenol compound is not evenly dispersed. can.

The melting point of component (B) is usually 70-300°C, preferably 100-250°C. If the temperature is lower than 70° C., it is completely melted by the heat during kneading, making it difficult to maintain the crystallinity. If the temperature is higher than 300° C., the crystals do not melt and are not uniformly dispersed during curing and molding, making it difficult to produce a homogeneous cured product from this molding material.
The melting point can be determined from the endothermic peak temperature using, for example, a commercially available differential scanning calorimeter (DSC).

In order to improve fluidity, the molecular weight of component (B) is preferably as small as possible, preferably 190-400, more preferably 210-350, particularly preferably 240-300.
Further, the hydroxyl equivalent of component (B) is 95 to 200 g/eq. is preferably 105 to 175 g/eq. is more preferably 120 to 150 g/eq. is particularly preferred.

Further, in the component (B), the number of substituted alkyl groups is preferably 2-6. From the viewpoint of crystallinity, the number of substituted alkyl groups is preferably an even number of 2, 4, or 6. The substituted alkyl group is preferably an alkyl group having 1 to 6 carbon atoms, such as methyl group, ethyl group, phenyl group and allyl group.
Specific examples include dimethylbiphenol, tetramethylbiphenol, diallylbiphenol, diethylbiphenol, tetraethylbiphenol and diphenylbiphenol.
In the present invention, when the substituted alkyl group is a methyl group or an ethyl group, a 4- to 6-substituted biphenol compound is preferable, and when the substituted alkyl group is a phenyl group or an allyl group, a disubstituted biphenol compound is preferable. Disubstituted methyl or ethyl groups with small alkyl groups have high reactivity, so even if the molecular weight is small and the initial viscosity is low, the reactivity increases, and as a result, there is a risk that the fluidity will decrease. be.
On the other hand, a phenyl group or an allyl group having a large substituent group has a large effect, and tetra-substitution may conversely make the reaction difficult. The total carbon number of the substituent is preferably 2-12, more preferably 4-10.

The component (B) used in the present invention may be commercially available or may be produced by a known method. Specific compounds available as commercial products include, for example, 4,4'-dihydroxy-3,3',5,5'-tetramethylbiphenyl (manufactured by Tokyo Chemical Industry Co., Ltd.; melting point: 223-225°C; molecular weight: 242. 32 Total carbon number of substituents 4), 3,3'-dimethyl-4,4'-biphenol (manufactured by Songwon International Japan Co., Ltd. Melting point 162°C Molecular weight 214.26 Total carbon number of substituents 2), 4,4 '-dihydroxy-3,3'-diphenyldiphenyl (manufactured by Sanko Kagaku Co., Ltd.) melting point 147.7°C molecular weight 338.41 total carbon number of substituents 12), 3,3'-diallylbiphenyl-4,4'- Diol (manufactured by Mitsui Chemicals Fine Co., Ltd.; melting point: 76°C; molecular weight: 266.34; total carbon number of substituents: 6);

The phenolic resin mixture of the present invention is obtained by uniformly mixing component (A) and component (B).
However, it is preferable to mix at a temperature below the melting point of the component (B) and knead and mix so that the crystals are dispersed. Specifically, it is preferable to knead the mixture at a temperature below the melting point of the crystalline alkyl-substituted bifer compound and use it as an organic filler. In this case, if the crystals are not homogeneously dispersed, the ratio of the blended components (A) and (B) will change, which is undesirable because partial curing failure will occur.
Specifically, it is preferable to knead at a temperature lower than 100°C. If the temperature exceeds 100°C, aggregation of the crystalline phenolic resin proceeds during cooling to room temperature, and the crystals are not uniformly dispersed. In addition, when heated and melted, it affects the stickiness of the obtained phenolic resin mixture, making it difficult to take out. Furthermore, there is a risk of productivity problems, such as difficulty in charging into the inlet. Therefore, in the present invention, kneading/mixing at a temperature below the melting point is preferred.

The obtained tablet-like, powder-like, sheet-like or granular mixture is characterized by being non-sticky even when stored at 20°C.
In kneading and mixing, the phenolic resin mixture can be obtained by sufficiently mixing using an extruder, a kneader, a roll, or the like.

In the phenolic resin mixture of the present invention, the weight ratio of component (A) and component (B) is usually 95/5 to 85/15, preferably 90/10 to 85/15. If the weight ratio of component (A) is greater than 95, fluidity will be poor. On the other hand, if the weight ratio of component (A) is less than 85, part of the phenolic resin mixture will crystallize unevenly at 20°C. That is, when the weight ratio of component (A) and component (B) is 95/5 to 85/15, it has fluidity at high temperatures and becomes non-sticky and uniform semi-crystalline at 20°C. Therefore, it has both fluidity and handling.

The hydroxyl equivalent of the phenolic resin mixture of the present invention is preferably 130-200 g/eq, more preferably 163-200/eq, and particularly preferably 186-200 g/eq. If the hydroxyl equivalent is less than 130 g/eq, the functional groups are contained in a large amount, so that the curing speed is increased, and sufficient fluidity may not be obtained. On the other hand, when the hydroxyl equivalent is more than 200 g/eq, the curability is poor and sufficient hardness may not be obtained.

The ICI melt viscosity (cone plate method) at 150° C. of the present invention is preferably 0.001 to 0.20 Pa s, more preferably 0.005 to 0.15 Pa s, particularly preferably 0.01 to It is 0.1 Pa·s. When the ICI melt viscosity is lower than 0.001 Pa s, the melt viscosity is too low to maintain the dispersed state of the filler. The shrinkage rate of the encapsulating material increases.

The curable resin composition of the present invention contains an epoxy resin.
Specific examples of epoxy resins that can be used include novolac type epoxy resins, bisphenol A type epoxy resins, biphenyl type epoxy resins, triphenylmethane type epoxy resins, and phenol aralkyl type epoxy resins. Specifically, bisphenol A, bisphenol S, thiodiphenol, fluorene bisphenol, terpene diphenol, 4,4′-biphenol, 2,2′-biphenol, 3,3′,5,5′-tetramethyl-[ 1,1'-biphenyl]-4,4'-diol, hydroquinone, resorcinol, naphthalenediol, tris-(4-hydroxyphenyl)methane, 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane, phenol (phenol, alkyl-substituted phenol, naphthol, alkyl-substituted naphthol, dihydroxybenzene, dihydroxynaphthalene, etc.) and formaldehyde, acetaldehyde, benzaldehyde, p-hydroxybenzaldehyde, o-hydroxybenzaldehyde, p-hydroxyacetophenone, o-hydroxyacetophenone, dicyclo pentadiene, furfural, 4,4'-bis(chloromethyl)-1,1'-biphenyl, 4,4'-bis(methoxymethyl)-1,1'-biphenyl, 1,4-bis(chloromethyl)benzene, Polycondensates with 1,4-bis(methoxymethyl)benzene and the like and modified products thereof, halogenated bisphenols such as tetrabromobisphenol A, glycidyl ethers derived from alcohols, alicyclic epoxy resins, glycidyl Silsesquioxane-based epoxy resins such as amine-based epoxy resins, glycidyl ester-based epoxy resins (chain-like, cyclic, ladder-like, or a mixture of at least two or more of these siloxane structures with glycidyl groups and/or epoxycyclohexane solid or liquid epoxy resins such as structured epoxy resins), but are not limited thereto.
However, it is preferable that the softening point of all the epoxy resins used is 40 to 180° C. when melt-mixed. Especially preferred is 40 to 150°C.

The curable resin composition of the invention may contain an inorganic filler. Inorganic fillers include powders of crystalline silica, fused silica, alumina, zircon, calcium silicate, calcium carbonate, silicon carbide, silicon nitride, boron nitride, zirconia, fosterite, steatite, spinel, titania, talc, etc. Beads formed by spheroidizing are included, but are not limited to these. These may be used independently and may use 2 or more types. In the present invention, crystalline silica, fused silica, and alumina are preferred from the viewpoint of the balance of properties when it is assumed to be used as a semiconductor sealing material.
The content of these inorganic fillers is preferably 70 to 96% by mass with respect to 100% by mass of the curable resin composition of the present invention. In particular, it is preferably 70 to 93% by mass. In the present invention, since the fluidity is particularly high, if the amount of the inorganic filler is too small, the balance between the inorganic filler and the resin is disturbed, resulting in portions with a large amount of inorganic filler and portions with a small amount of inorganic filler in the molded product of the resin composition. Unfavorable in terms of iso-characteristics.
Moreover, if the content of the inorganic filler exceeds 96%, it is not preferable because the fluidity cannot be obtained.

In the curable resin composition of the present invention, the phenolic resin mixture acts as a curing agent for the epoxy resin. In the present invention, as a curing agent, not only the phenolic resin mixture of the present invention, but also other curing agents may be used in combination.
Other curing agents that can be used include phenolic compounds other than the phenolic resin of the present invention, amine compounds, acid anhydride compounds, amide compounds, carboxylic acid compounds, and the like. Examples of phenolic resins and phenolic compounds include bisphenol A, bisphenol F, 3,3'-dimethyl-4,4'-bisphenol A, 3,3'-dimethyl-4,4'-bisphenol F, 3,3' , 5,5′-tetramethyl-4,4′-bisphenol A, 3,3′,5,5′-tetramethyl-4,4′-bisphenol F, bisphenol S, fluorene bisphenol, terpene diphenol, 4, 4'-biphenol, 2,2'-biphenol, hydroquinone, resorcinol, naphthalenediol, tris-(4-hydroxyphenyl)methane, 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane, phenols (phenol , alkyl-substituted phenol, naphthol, alkyl-substituted naphthol, dihydroxybenzene, dihydroxynaphthalene, etc.) and formaldehyde, acetaldehyde, benzaldehyde, p-hydroxybenzaldehyde, o-hydroxybenzaldehyde, p-hydroxyacetophenone, o-hydroxyacetophenone, dicyclopentadiene, furfural , 4,4′-bis(chloromethyl)-1,1′-biphenyl, 4,4′-bis(methoxymethyl)-1,1′-biphenyl, 1,4′-bis(chloromethyl)benzene, 1 , 4'-bis(methoxymethyl)benzene and other polycondensates and modified products thereof, halogenated bisphenols such as tetrabromobisphenol A, and polyphenols such as condensates of terpene and phenols. is not limited to These may be used independently and may use 2 or more types.
Preferable phenol resins include phenol aralkyl resins (resins having an aromatic alkylene structure), and particularly preferably a structure having at least one selected from phenol, naphthol, and cresol, the alkylene moiety serving as a linker being benzene. structure, biphenyl structure, and naphthalene structure (specifically, Zyloc, naphthol Zyloc, phenolbiphenylene novolak resin, cresol-biphenylene novolak resin, phenol-naphthalene novolak resin, etc.) It is possible.).

Examples of amine-based compounds and amide-based compounds include nitrogen-containing compounds such as diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, dicyandiamide, and polyamide resin synthesized from a dimer of linolenic acid and ethylenediamine. mentioned.
Acid anhydride compounds and carboxylic acid compounds include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methyl nadic anhydride, and nadic anhydride. , hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, butanetetracarboxylic anhydride, bicyclo[2,2,1]heptane-2,3-dicarboxylic anhydride, methylbicyclo[2,2,1]heptane- Acid anhydrides such as 2,3-dicarboxylic anhydride, cyclohexane-1,3,4-tricarboxylic acid-3,4-anhydride; addition of various alcohols, carbinol-modified silicones, and the aforementioned acid anhydrides Examples include carboxylic acid resins obtained by reaction.
Other examples include imidazole, trifluoroborane-amine complexes, and guanidine derivative compounds.
The above and other curing agents are not limited to these. Moreover, these may be used independently and may use 2 or more types. In the present invention, it is particularly preferable to use a phenolic compound from the aspect of reliability.

In the curable resin composition of the present invention, the amount of the epoxy resin and the curing agent used is preferably 0.7 to 1.2 equivalents per equivalent of the epoxy group of the total epoxy resin. If the amount is less than 0.7 equivalents or if the amount exceeds 1.2 equivalents with respect to 1 equivalent of the epoxy group, curing may be incomplete and good cured physical properties may not be obtained.

The curable resin composition of the present invention may further contain a curing accelerator.
Specific examples of curing accelerators that can be used include imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-(dimethylaminomethyl)phenol, 1,8-diaza -tertiary amines such as bicyclo(5,4,0)undecene-7, phosphines such as triphenylphosphine, tetrabutylammonium salts, triisopropylmethylammonium salts, trimethyldecanylammonium salts, cetyltrimethylammonium salts, etc. and quaternary phosphonium salts such as quaternary ammonium salts, triphenylbenzylphosphonium salts, triphenylethylphosphonium salts, and tetrabutylphosphonium salts. The counter ions of the quaternary salt are halogen, organic acid ions, hydroxide ions, and the like, and are not particularly specified, but organic acid ions and hydroxide ions are particularly preferred. metal compounds such as tin octylate; The curing accelerator is used in an amount of 0.01 to 5.0 parts by mass based on 100 parts by mass of the epoxy resin.

Further, the curable resin composition of the present invention contains various additives such as release agents such as silane coupling agents, stearic acid, palmitic acid, zinc stearate and calcium stearate, surfactants, dyes, pigments and ultraviolet absorbers. Compounding agents and various thermosetting resins can be added.

Further, the curable resin composition of the present invention can be blended with a binder resin as needed. Examples of binder resins include butyral resins, acetal resins, acrylic resins, epoxy-nylon resins, NBR-phenol resins, epoxy-NBR resins, polyamide resins, polyimide resins, and silicone resins. , but not limited to these. The blending amount of the binder resin is preferably within a range that does not impair the flame retardancy and heat resistance of the cured product. Parts by mass are used as needed.

The curable resin composition of the present invention can contain a known maleimide compound as necessary. Specific examples of usable maleimide compounds include 4,4′-diphenylmethanebismaleimide, polyphenylmethanemaleimide, m-phenylenebismaleimide, 2,2′-bis[4-(4-maleimidophenoxy)phenyl]propane, 3 ,3′-dimethyl-5,5′-diethyl-4,4′-diphenylmethanebismaleimide, 4-methyl-1,3-phenylenebismaleimide, 4,4′-diphenyletherbismaleimide, 4,4′-diphenylsulfone Bismaleimide, 1,3-bis(3-maleimidophenoxy)benzene, 1,3-bis(4-maleimidophenoxy)benzene, biphenylaralkyl-type maleimide, etc., but not limited thereto. These may be used alone or in combination of two or more. When blending the maleimide-based compound, a curing accelerator may be blended as necessary, and the above-mentioned curing accelerators, organic peroxides, radical polymerization initiators such as azo compounds, and the like can be used.

The curable resin composition of the present invention is obtained by uniformly mixing the above-mentioned respective components in a predetermined ratio, usually precured at 130 to 180 ° C. for 30 to 500 seconds, and further cured at 150 to 200 ° C. After curing for 2 to 15 hours at , the curing reaction proceeds sufficiently to obtain the cured product of the present invention. It is also possible to uniformly disperse or dissolve the components of the curable resin composition in a solvent or the like, remove the solvent, and then cure the composition.

The curable resin composition of the present invention thus obtained has moisture resistance, heat resistance, high adhesiveness, low dielectric constant and low dielectric loss tangent. Therefore, the curable resin composition of the present invention can be used in a wide range of fields requiring moisture resistance, heat resistance, high adhesiveness, low dielectric constant and low dielectric loss tangent. Specifically, it is useful as an insulating material, laminate (printed wiring board, BGA substrate, build-up substrate, etc.), sealing material, resist, and all other materials for electrical and electronic parts. In addition to molding materials and composite materials, it can also be used in fields such as paint materials, adhesives, and 3D printing. Particularly in semiconductor encapsulation, solder reflow resistance is beneficial.

A semiconductor device has one sealed with the curable resin composition of the present invention. Examples of semiconductor devices include DIP (dual in-line package), QFP (quad flat package), BGA (ball grid array), CSP (chip size package), SOP (small outline package), TSOP (thin small outline package), and TQFP. (think quad flat package) and the like.

Although the method for preparing the curable resin composition of the present invention is not particularly limited, it may be prepared by dispersing or dissolving each component in a solvent or the like, uniformly mixing, and optionally distilling off the solvent. , or may be prepolymerized. For example, the phenolic resin mixture epoxy resin of the present invention, amine compounds, maleimide compounds, cyanate ester compounds, phenolic resins, curing agents such as acid anhydride compounds, and other additives may be heated in the presence or absence of a solvent. prepolymerized by addition. Mixing or prepolymerization of each component is carried out by using, for example, an extruder, kneader, rolls, etc. in the absence of a solvent, and by using a reactor equipped with a stirrer in the presence of a solvent.

As a method for uniform mixing without using a solvent, etc., a uniform curable resin composition is obtained by kneading using a device such as a kneader, roll, planetary mixer, etc. at a temperature within the range of 50 to 100 ° C. do. After pulverizing the obtained curable resin composition, it is molded into a cylindrical tablet by a molding machine such as a tablet machine, or it is made into a granular powder or a powdery molding, or these compositions are used as a surface support. It is also possible to form a sheet having a thickness of 0.05 mm to 10 mm by melting above and forming a curable resin composition molded body. The obtained molded article becomes a non-sticky molded article at 0 to 20°C, and its fluidity and curability hardly deteriorate even when stored at -25 to 0°C for 1 week or longer.
The resulting molded product can be molded into a cured product using a transfer molding machine or a compression molding machine.

An organic solvent can be added to the curable resin composition of the present invention to form a varnish-like composition (hereinafter simply referred to as varnish). If necessary, the curable resin composition of the present invention is dissolved in a solvent such as toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc. to form a varnish. , Polyester fiber, polyamide fiber, alumina fiber, paper, etc., is impregnated into a base material and heat-dried to obtain a prepreg, which is hot-press molded to obtain a cured product of the curable resin composition of the present invention. . In this case, the solvent is usually used in an amount of 10 to 70% by weight, preferably 15 to 70% by weight in the mixture of the curable resin composition of the present invention and the solvent. If the amount of solvent is less than this range, the viscosity of the varnish will increase and the workability will be deteriorated. Moreover, if it is a liquid composition, it is possible to obtain a curable resin-cured product containing carbon fibers by, for example, the RTM method.

The cured product of the present invention can be used for various purposes.
For example, adhesives, paints, coating agents, molding materials (including sheets, films, FRP, etc.), insulating materials (including printed circuit boards, wire coatings, etc.), sealants, additives to other resins, etc. is mentioned. Adhesives include adhesives for civil engineering, construction, automobiles, general office and medical use, as well as adhesives for electronic materials. Among them, adhesives for electronic materials include interlayer adhesives for multilayer substrates such as build-up substrates, die bonding agents, adhesives for semiconductors such as underfill, underfill for BGA reinforcement, anisotropic conductive films ( ACF), mounting adhesives such as anisotropic conductive paste (ACP), and the like.
In particular, in the present invention, it is mainly used as a sealing material for semiconductors, but it can also be used as a substrate or as a mold underfill (MUF).

Specifically, the main applications of encapsulants currently in use are potting, dipping, transfer molding encapsulation for capacitors, transistors, diodes, light-emitting diodes, ICs, LSIs, IC packages such as QFPs, BGAs, and CSPs. Examples include sealing (including reinforcing underfill) at the time of similar mounting.

EXAMPLES Next, the present invention will be described in more detail with reference to examples. In the following, parts are parts by mass unless otherwise specified. However, the present invention is not limited to these examples.
Various analysis methods used in the examples are described below.
ICI melt viscosity: conforms to JIS K 7117-2 (ISO3219)

[Examples 1 to 4, Comparative Examples 1 to 3]
KAYAHARD GPH-65 (phenolic resin represented by the above formula (1), manufactured by Nippon Kayaku Co., Ltd., melting point 65 ° C.), MEHC-7840-4S (phenolic resin represented by the above formula (2), Meiwa Kasei Co., Ltd. company, melting point 58-65°C), 4,4'-dihydroxy-3,3',5,5'-tetramethylbiphenyl (abbreviation: TMBP, manufactured by Tokyo Chemical Industry Co., Ltd. melting point 223-225°C, molecular weight 242. 32 Substituents having a total carbon number of 4) were kneaded and mixed with a mixing roll at 80° C. for 15 minutes at the ratio shown in Table 1 to prepare a phenolic resin mixture.

[Appearance observation]
The appearance of the obtained phenol resin mixture was visually observed at room temperature (20° C.).
When there were no lumps of crystals, that is, when the component (B) was uniformly dispersed while maintaining the crystalline state, it was evaluated as ◯, and when there were lumps of crystals, it was evaluated as x.

[Stickiness]
The surface stickiness of the obtained tablets was evaluated. As an evaluation method, the obtained tablet was pressed with a finger for 10 seconds to evaluate the degree of stickiness of the coating film.
◯: The surface was non-sticky and smooth.
Δ: Sticky, but does not stick to fingers.
x: Extremely sticky and sticks to fingers.

[Examples 5 and 6, Comparative Example 4]
[Spiral flow test]
Epoxy resin, phenol resin mixture (Examples 3 and 4 and Comparative Example 3), silica filler, and curing accelerator in the ratio shown in Table 2 were kneaded and mixed by a mixing roll at 80°C for 25 minutes. Subsequently, using an Archimedes spiral mold and a transfer molding machine, a spiral flow test was conducted under the following conditions.
Mold: Conforming to EMMI-1-66 Mold temperature: 175°C
Transfer pressure: 70 kgf/cm ²
Press: 5t press, pot diameter: 30mm
Injection time: 1 second Molding time: 120 seconds

[gel time]
Place an appropriate amount of the curable resin composition shown in Table 2 on a hot plate at 175 ° C with a metal spatula and stir with a metal spatula until the sample becomes tacky and peels off from the hot plate. The time when the sex disappeared was measured.

In the spiral flow test, the higher the value, the better the fluidity. The gel time is the time required for the sealing material to lose its fluidity when heated at a constant temperature, and can be appropriately selected in relation to curing properties.

NC-3000: biphenyl aralkyl type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 277 g / eq)
MSR-2102: High-purity spherical silica filler (manufactured by Tatsumori Co., Ltd.)
TPP: Triphenylphosphine (manufactured by Junsei Chemical Co., Ltd.)

From Tables 1 and 2, it was confirmed that the phenolic resin mixture of the present invention has excellent handleability and fluidity.

Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.
This application is based on a Japanese patent application (Japanese Patent Application No. 2021-048212) filed on March 23, 2021, the entirety of which is incorporated by reference. Also, all references cited herein are incorporated in their entirety.

From the above, it can be seen that the phenolic resin mixture of the present invention has excellent productivity and moldability while having high fluidity and handleability. Therefore, the curable resin composition of the present invention can be used for insulating materials for electric and electronic parts, laminates (printed wiring boards, build-up boards, etc.) and carbon fiber reinforced composite materials (hereinafter also referred to as "CFRP"). It is useful for various composite materials, adhesives, paints, etc. It is particularly useful as a semiconductor encapsulating material for protecting semiconductor elements.

Claims

containing a phenolic resin (A) represented by the following formula (1) or the following formula (2) and a crystalline alkyl-substituted biphenol compound (B) having a melting point of 70 to 300° C.; Phenolic resin mixtures in which the weight ratio of component (B) is from 95/5 to 85/15.

(In formula (1), multiple R 1 and p exist independently, and R 1 is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, a methoxy group, an ethoxy group, a nitro group, a nitrile group, an amino group, or a phenyl group which may have the same substituents as described above, p is a real number of 0 to 3. n is a repeating number and is a real number of 1 to 20.)

(In formula (2), multiple R 1 and p exist independently, and R 1 is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, a methoxy group, an ethoxy group, a nitro group, a nitrile group, an amino group, or a phenyl group which may have the same substituents as described above, p is a real number of 0 to 3. n is a repeating number and is a real number of 1 to 20.)
The phenolic resin mixture according to claim 1, which exhibits a semi-crystalline state at 20°C and has a hydroxyl equivalent of 130 to 200 g/eq.
The phenolic resin mixture according to claim 1 or 2, which has an ICI melt viscosity (cone plate method) at 150°C of 0.001 to 0.20 Pa·s.
A curable resin composition containing the phenolic resin mixture according to any one of claims 1 to 3 and an epoxy resin.
A cured product obtained by curing the curable resin composition according to claim 4 .